Article
Chemistry, Multidisciplinary
Oussama Moutanabbir, Simone Assali, Anis Attiaoui, Gerard Daligou, Patrick Daoust, Patrick Del Vecchio, Sebastian Koelling, Lu Luo, Nicolas Rotaru
Summary: This work demonstrates the epitaxial growth of Ge-70/silicon-germanium (SiGe) quantum wells with depleted Ge-73 and Si-29 isotopes, achieving nuclear spin-free Ge qubits. The study shows that the isotopic purity of the quantum wells is highly sensitive to the growth conditions.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Ella Schneider, Jonathan England
Summary: 28Si enrichment is crucial for quantum computers based on group IV semiconductors. A novel enrichment process involving ion implantation of 28Si into Al films deposited on native-oxide free Si substrates followed by layer exchange crystallization is reported. The process shows potential to produce quantum grade 28Si using conventional semiconductor foundry equipment within production-worthy time scales.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Multidisciplinary
Alec Jenkins, Joanna W. Lis, Aruku Senoo, William F. McGrew, Adam M. Kaufman
Summary: This study reports a fast, scalable, and high-fidelity qubit architecture based on 171Yb atoms, and proposes a near-deterministic loading protocol that is expected to play an important role in quantum simulation and information applications.
Article
Multidisciplinary Sciences
Katrina Barnes, Peter Battaglino, Benjamin J. Bloom, Kayleigh Cassella, Robin Coxe, Nicole Crisosto, Jonathan P. King, Stanimir S. Kondov, Krish Kotru, Stuart C. Larsen, Joseph Lauigan, Brian J. Lester, Mickey McDonald, Eli Megidish, Sandeep Narayanaswami, Ciro Nishiguchi, Remy Notermans, Lucas S. Peng, Albert Ryou, Tsung-Yao Wu, Michael Yarwood
Summary: This study introduces a qubit encoded in the nuclear spin states of a single Sr-87 atom and demonstrates long coherence time in a register of individually-controlled qubits. The researchers achieve comparable coherence times while driving multiple qubits in parallel. They suggest that nuclear spin qubits will combine with technical advances to accelerate the realization of intermediate-scale quantum information processors.
NATURE COMMUNICATIONS
(2022)
Article
Quantum Science & Technology
C. E. Bradley, S. W. de Bone, P. F. W. Moller, S. Baier, M. J. Degen, S. J. H. Loenen, H. P. Bartling, M. Markham, D. J. Twitchen, R. Hanson, D. Elkouss, T. H. Taminiau
Summary: We demonstrate the robustness of a C-13-spin quantum memory in isotopically engineered diamond to the optical link operation of a nitrogen-vacancy centre. The memory lifetime is significantly improved, surpassing reported times for entanglement distribution. Additionally, we show that the nuclear-spin state can survive ionisation and recapture of the nitrogen-vacancy electron. Combining this memory with previously demonstrated entanglement links and gates can enable key network primitives, paving the way for test-bed quantum networks capable of investigating complex algorithms and error correction.
NPJ QUANTUM INFORMATION
(2022)
Article
Physics, Multidisciplinary
Yang He, Na Li, Ivano E. Castelli, Ruoning Li, Yajie Zhang, Xue Zhang, Chao Li, Bingwu Wang, Song Gao, Lianmao Peng, Shimin Hou, Ziyong Shen, Jing-Tao Lu, Kai Wu, Per Hedegard, Yongfeng Wang
Summary: Investigation of intermolecular electron spin interaction is fundamental in science and technology. In this study, radical pairs of all-trans retinoic acid molecules were created on Au(111) and antiferromagnetic coupling between two radicals was identified. The coupling is mediated through O-H hydrogen bonds.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Ye-Bin Hu, Rong Chen, Guo-Qing Yan, Xing-Yu Zhu
Summary: Electron spin qubits in silicon quantum dots are a promising option for large-scalable quantum computation. Achieving spatially separated two-qubit gates and entanglement with high fidelity is crucial for quantum information processing based on these qubits. In this study, we investigate the long-range two-qubit iSWAP gate mediated by virtual microwave photons in a spin qubits-resonator system. Our results show that the entangling gate fidelity can reach 91.0% under realistic experimental conditions, and we analyze the factors that limit the fidelity. Furthermore, we numerically demonstrate the generation of remote Bell entangled states of spin qubits with high fidelity. This spin-resonator architecture also has the potential to implement quantum algorithms using the proposed scheme.
MODERN PHYSICS LETTERS A
(2023)
Article
Optics
Xiruo Yan, Sebastian Gitt, Becky Lin, Donald Witt, Mahssa Abdolahi, Abdelrahman Afifi, Adan Azem, Adam Darcie, Jingda Wu, Kashif Awan, Matthew Mitchell, Andreas Pfenning, Lukas Chrostowski, Jeff F. Young
Summary: Universal quantum computing has the potential to revolutionize the information-based society, but a hardware platform for fault-tolerant quantum computing remains elusive. One proposed platform involves using circuit-bound photons and solid-state spin qubits for measurement-based quantum computations, but practical implementation faces challenges. Silicon is identified as a leading candidate for hosting such a platform.
Article
Physics, Applied
J. S. Rojas-Arias, A. Noiri, P. Stano, T. Nakajima, J. Yoneda, K. Takeda, T. Kobayashi, A. Sammak, G. Scappucci, D. Loss, S. Tarucha
Summary: In this study, we detected correlations in qubit-energy fluctuations of non-neighboring qubits in isotopically purified Si/Si-Ge quantum dots. The correlation coefficient reached 10% for a next-nearest-neighbor qubit-pair separated by 200 nm at low frequencies where the noise is strongest. We also found correlations with the charge-sensor signal reaching up to 70%, proving the electrical origin of the observed noise. A simple theoretical model accurately reproduced the measurements and predicted a polynomial decay of correlations with interqubit distance. These results quantify the long-range correlations of noise in quantum-dot spin-qubit arrays, which are essential for scalability and fault tolerance.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Multidisciplinary
Teresa Hoenigl-Decrinis, Ilya Antonov, Rais Shaikhaidarov, Kyung Ho Kim, Vladimir N. Antonov, Oleg Astafiev
Summary: We demonstrate the capacitive coupling of coherent quantum phase slip (CQPS) flux qubits to a resonator. Our results show that the coupling strength does not depend on the qubit's energy, which provides flexibility in material and design choices for CQPS-based devices. This is the first report of CQPS in TiN and the first demonstration of capacitive coupling of a CQPS flux qubit.
NEW JOURNAL OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ji Zou, Shu Zhang, Yaroslav Tserkovnyak
Summary: We theoretically investigate the dynamics of two spin qubits interacting with a magnetic medium. We show that a sizable long-lived entanglement can be established between the spin qubits via the magnetic environment, in the absence of any coherent coupling. Moreover, we demonstrate that maximally entangled two-qubit states can be achieved in this scheme when complemented by proper postselection.
Article
Quantum Science & Technology
Abhikbrata Sarkar, Joel Hochstetter, Allen Kha, Xuedong Hu, Michelle Y. Simmons, Rajib Rahman, Dimitrie Culcer
Summary: Multi-donor quantum dots play a crucial role in the development of Si-based quantum computation. Specifically, 2P:1P spin qubits with built-in dipole moment are suitable for electron dipole spin resonance (EDSR) due to the donor hyperfine interaction. The fastest EDSR time occurs when the 2P:1P axis is parallel to [111], while the best Rabi ratio occurs when it is parallel to [100]. The qubit is robust against 1/f noise if operated away from the charge anti-crossing. Entanglement via exchange is significantly faster than dipole-dipole coupling.
NPJ QUANTUM INFORMATION
(2022)
Article
Materials Science, Multidisciplinary
Wei Xiong, Jiaojiao Chen, Baolong Fang, Mingfeng Wang, Liu Ye, J. Q. You
Summary: In this study, a method to greatly enhance the interaction between two single NV spins in diamond is proposed. By optimizing the interaction between NV spin and the electromechanical cavity, a strong coupling between the spins is achieved, enabling coherent quantum-information exchange.
Article
Materials Science, Multidisciplinary
Stephen R. McMillan, Guido Burkard
Summary: A critical element for scalable quantum processors is the nonlocal coupling between nodes. Recent research has shown that spin-based qubits in double quantum dot architectures can exhibit spin-spin interactions via the exchange of photons. This study proposes a framework for a resonant direct-CNOT operation between nonlocal single-spin qubits.
Article
Materials Science, Multidisciplinary
Vivek Mishra, Yu Li, Fu-Chun Zhang, Stefan Kirchner
Summary: We investigate the effect of spin-orbit coupling on proximity-induced superconductivity in a normal metal attached to a superconductor. Specifically, we consider a heterostructure with Rashba spin-orbit coupling due to the presence of interfaces. The properties of the induced superconductivity and the effect of impurity scattering are addressed within the tunneling Hamiltonian formalism, with the finding of a mixture of singlet and triplet pairing.
Article
Instruments & Instrumentation
C. Adambukulam, V. K. Sewani, H. G. Stemp, S. Asaad, M. T. Madzik, A. Morello, A. Laucht
Summary: Magnetic fields are essential tools in physics for material characterization and spin polarization experiments. This permanent magnet assembly can achieve high magnetic field strengths and serve as a cost-effective alternative to bulky superconducting solenoids for spin qubit experiments.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Chemistry, Multidisciplinary
Alexander M. Jakob, Simon G. Robson, Vivien Schmitt, Vincent Mourik, Matthias Posselt, Daniel Spemann, Brett C. Johnson, Hannes R. Firgau, Edwin Mayes, Jeffrey C. McCallum, Andrea Morello, David N. Jamieson
Summary: This study discusses the material choice of silicon chips containing arrays of single dopant atoms for classical and quantum devices, as well as the method of near-surface implantation of single ions and the associated physics model and limiting factors.
ADVANCED MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
A. V. Chumak, P. Kabos, M. Wu, C. Abert, C. Adelmann, A. O. Adeyeye, J. Akerman, F. G. Aliev, A. Anane, A. Awad, C. H. Back, A. Barman, G. E. W. Bauer, M. Becherer, E. N. Beginin, V. A. S. V. Bittencourt, Y. M. Blanter, P. Bortolotti, I. Boventer, D. A. Bozhko, S. A. Bunyaev, J. J. Carmiggelt, R. R. Cheenikundil, F. Ciubotaru, S. Cotofana, G. Csaba, O. V. Dobrovolskiy, C. Dubs, M. Elyasi, K. G. Fripp, H. Fulara, I. A. Golovchanskiy, C. Gonzalez-Ballestero, P. Graczyk, D. Grundler, P. Gruszecki, G. Gubbiotti, K. Guslienko, A. Haldar, S. Hamdioui, R. Hertel, B. Hillebrands, T. Hioki, A. Houshang, C. -M. Hu, H. Huebl, M. Huth, E. Iacocca, M. B. Jungfleisch, G. N. Kakazei, A. Khitun, R. Khymyn, T. Kikkawa, M. Klaui, O. Klein, J. W. Klos, S. Knauer, S. Koraltan, M. Kostylev, M. Krawczyk, I. N. Krivorotov, V. V. Kruglyak, D. Lachance-Quirion, S. Ladak, R. Lebrun, Y. Li, M. Lindner, R. Macedo, S. Mayr, G. A. Melkov, S. Mieszczak, Y. Nakamura, H. T. Nembach, A. A. Nikitin, S. A. Nikitov, V. Novosad, J. A. Otalora, Y. Otani, A. Papp, B. Pigeau, P. Pirro, W. Porod, F. Porrati, H. Qin, B. Rana, T. Reimann, F. Riente, O. Romero-Isart, A. Ross, A. V. Sadovnikov, A. R. Safin, E. Saitoh, G. Schmidt, H. Schultheiss, K. Schultheiss, A. A. Serga, S. Sharma, J. M. Shaw, D. Suess, O. Surzhenko, K. Szulc, T. Taniguchi, M. Urbanek, K. Usami, A. B. Ustinov, T. van der Sar, S. van Dijken, V. I. Vasyuchka, R. Verba, S. Viola Kusminskiy, Q. Wang, M. Weides, M. Weiler, S. Wintz, S. P. Wolski, X. Zhang
Summary: Magnonics is a discipline that explores the physical properties of spin waves and utilizes them for data processing. It offers several advantages, such as scalability to atomic dimensions, operation in high-frequency ranges, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS technology. Although primarily in the academic domain, extensive research is being conducted to address the scientific and technological challenges, with several proof-of-concept prototypes already realized in laboratories.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Multidisciplinary Sciences
Mateusz T. Madzik, Serwan Asaad, Akram Youssry, Benjamin Joecker, Kenneth M. Rudinger, Erik Nielsen, Kevin C. Young, Timothy J. Proctor, Andrew D. Baczewski, Arne Laucht, Vivien Schmitt, Fay E. Hudson, Kohei M. Itoh, Alexander M. Jakob, Brett C. Johnson, David N. Jamieson, Andrew S. Dzurak, Christopher Ferrie, Robin Blume-Kohout, Andrea Morello
Summary: This study demonstrates universal quantum logic operations using nuclear spins in a silicon nanoelectronic device, achieving high-fidelity entangled states. The precise characterization of quantum operations shows that nuclear spins are approaching the performance required for fault-tolerant quantum processors. Additionally, the entanglement between nuclear spins and electron spins is also demonstrated. The results establish a viable route for scalable quantum information processing using donor nuclear and electron spins.
Article
Multidisciplinary Sciences
Thomas Luschmann, Philip Schmidt, Frank Deppe, Achim Marx, Alvaro Sanchez, Rudolf Gross, Hans Huebl
Summary: The study investigates an inductively coupled nano-electromechanical system using a superconducting quantum interference device (SQUID) for coupling, showing that the resonance frequency of the mechanically compliant string embedded into the SQUID loop can be controlled by adjusting the bias magnetic flux and in-plane bias magnetic field. These findings are quantitatively explained by the inductive interaction contributing to the effective spring constant of the mechanical resonator, with an additional observation of a residual field dependent shift in the mechanical resonance frequency attributed to flux pinning of vortices trapped in the nanostring under bias.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Applied
Daniel J. Parker, Mykhailo Savytskyi, Wyatt Vine, Arne Laucht, Timothy Duty, Andrea Morello, Arne L. Grimsmo, Jarryd J. Pla
Summary: Degenerate parametric amplifiers (DPAs) exhibit phase-sensitive gain and have been utilized in various applications. This study investigates a microwave DPA utilizing nonlinearity from kinetic inductance with high dynamic range and squeezing potential. The amplifier shows promising performance near quantum noise limit and minimal higher-order nonlinearities, making it a potential candidate for future applications.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Mark A. Johnson, Mateusz T. Madzik, Fay E. Hudson, Kohei M. Itoh, Alexander M. Jakob, David N. Jamieson, Andrew Dzurak, Andrea Morello
Summary: This article presents a method for initializing quantum states with a fidelity beyond the thermal limit using real-time monitoring and negative-result measurement. The experimental results show that this method can reduce initialization errors and improve fidelity by increasing the bandwidth of the amplifier chain or slowing down electron tunneling rates.
Article
Physics, Applied
F. Engelhardt, V. A. S. V. Bittencourt, H. Huebl, O. Klein, S. Viola Kusminskiy
Summary: Developing schemes for efficient and broadband frequency conversion of quantum signals is a challenge in modern quantum information field. In this work, a two-stage conversion protocol is proposed using resonant interaction between magnetic and mechanical excitations as a mediator between microwave and optical photons. High conversion efficiency is predicted without the requirement of matching cooperativities.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
S. G. Robson, P. Raecke, A. M. Jakob, N. Collins, H. R. Firgau, V Schmitt, V Mourik, A. Morello, E. Mayes, D. Spemann, D. N. Jamieson
Summary: This study explores a feasible approach to create large-scale donor arrays in silicon devices by implanting low-energy ions and evaluating the device response characteristics using a specific characterization system.
PHYSICAL REVIEW APPLIED
(2022)
Article
Chemistry, Multidisciplinary
Zeheng Wang, MengKe Feng, Santiago Serrano, William Gilbert, Ross C. C. Leon, Tuomo Tanttu, Philip Mai, Dylan Liang, Jonathan Y. Huang, Yue Su, Wee Han Lim, Fay E. Hudson, Christopher C. Escott, Andrea Morello, Chih Hwan Yang, Andrew S. Dzurak, Andre Saraiva, Arne Laucht
Summary: This study investigates the potential of elongated quantum dots, known as jellybean quantum dots, as qubit-qubit couplers. Through experimental measurements and simulations, it is found that under low electron occupancies, the jellybean quantum dots form a tunable, artificial molecule composed of three coupled dots. Under high electron occupancies, they merge into one large dot with well-defined spin states, demonstrating the potential of jellybean dots as qubit couplers in future quantum computing architectures.
ADVANCED MATERIALS
(2023)
Article
Optics
Philip Daniel Blocher, Serwan Asaad, Vincent Mourik, Mark A. Johnson, Andrea Morello, Klaus Molmer
Summary: Out-of-time-ordered correlation functions (OTOCs) are crucial in studying quantum information scrambling, but are difficult to measure experimentally. This study proposes an OTOC measurement protocol that does not rely on time reversal and is applicable to various experimental settings and systems.
Article
Materials Science, Multidisciplinary
Richard Schlitz, Luise Siegl, Takuma Sato, Weichao Yu, Gerrit E. W. Bauer, Hans Huebl, Sebastian T. B. Goennenwein
Summary: This study explores the effect of phonon pumping on room-temperature ferromagnetic resonance spectra and finds the formation of magnon polarons at low frequencies and additional slowly oscillating phonon pumping at higher frequencies. Furthermore, the study also discovers the magnon-phonon coupling of a perpendicular standing spin wave mode.
Article
Materials Science, Multidisciplinary
Janine Gueckelhorn, Akashdeep Kamra, Tobias Wimmer, Matthias Opel, Stephan Gepraegs, Rudolf Gross, Hans Huebl, Matthias Althammer
Summary: The pseudospin of spin-up and spin-down magnons can describe the phenomena in antiferromagnets, which are similar to electronic charge carriers. The experimental study of the dynamics of antiferromagnetic pseudospin and the observation of the magnon Hanle effect have been reported. Platinum strips are used in the experiment to realize spin injection and detection, and their influence on the generation and transport of magnons in antiferromagnetic insulator films is investigated.
Article
Materials Science, Multidisciplinary
M. Mueller, T. Luschmann, A. Faltermeier, S. Weichselbaumer, L. Koch, G. B. P. Huber, H. W. Schumacher, N. Ubbelohde, D. Reifert, T. Scheller, F. Deppe, A. Marx, S. Filipp, M. Althammer, R. Gross, H. Huebl
Summary: In this study, we systematically investigated the performance of compact NbTiN microwave resonators under different temperature and magnetic field conditions. The results show that the resonators exhibit good quality factors and power factors at suitable temperatures.
MATERIALS FOR QUANTUM TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Ei Shigematsu, Lukas Liensberger, Mathias Weiler, Ryo Ohshima, Yuichiro Ando, Teruya Shinjo, Hans Huebl, Masashi Shiraishi
Summary: Semiconductor/ferromagnet hybrid systems are used to investigate spin conversion physics, but rectification currents have been a problem. A study on Si-based heterostructures using a microwave frequency inductive technique revealed the influence of Si doping on spin-orbit torque conductivity and observed a change in spin to charge conversion. These findings provide insights for further exploration of spin-conversion physics in metal/semiconductor heterostructures.
